The present invention relates to a process for preparing cocoa products having improved color. More specifically, the present invention relates to a process for preparing dutched or alkalized cocoa, having a deeper or more intense red or black color than has heretofor been available, for use in coloring and/or flavoring foodstuffs. Cocoa powders having intense colors are desirable, since foodstuffs prepared with these acquire an especially attractive, rich chocolate color. A great coloring capacity also makes these cocoa powders especially economical to use. As examples of applications of intensely alkalized cocoa powders the following can be mentioned: bakery products, desserts, ice cream, cocoa beverages, toppings for ice cream, biscuits, and confectionery and compound coatings. These intensely alkalized cocoa powders are usually used in products which need further preparation to obtain a consumable product, such as cake mixes, ice cream mixes, dessert powders and so-called instant cocoa mixes. These alkalized cocoa powders are utilized because of the attractive color and flavor they impart to the finished product.
The importance of the use of cocoa powders with great coloring capacity is highlighted by the general tendency to restrict the use of artificial colors, the use of which in the above foodstuffs is actually prohibited in many countries. It is, of course, also possible to mix cocoa powders with great coloring capacity and slightly alkalized or even non-alkalized cocoa powders, in order to obtain a mixture in which the advantages of both types of cocoas are combined.
Dutching, or the reacting of sodium, potassium, ammonium and magnesium compounds with cacao material such as cacao nibs, cocoa liquor or cocoa powder has been employed for many years to give cocoa powder a darker, richer color. A strong demand for extremely dark cocoa exists in the cookie trade since it is desirable for chocolate, sandwich-type cookies to have the darkest possible color.
In prior-art dutching processes, various cocoa materials, such as beans, nibs (fine or coarse), liquor or partly defatted liquor, or granulated or powdered cocoa press cake have been used Large or small quantities of water have been used with the full amount or only a portion of the permitted alkaline substances. The cocoa material may be partially or completely roasted, and of any type. Nibs and dry alkali have been mixed and treated with water or have been ground dry to a paste, which then may or may not be water-treated. The alkali has been added all at once or in stages. The processing has been in open, jacketed mixers, so that the moisture removal begins almost as soon as the water is added, or in closed mixers or kettles where the water may be retained until certain results are obtained. In addition to these variations, there have been both batch and continuous processes.
Classical prior art processes involve the treatment of cleaned, roasted cacao nibs with an alkali, such as potassium carbonate, at a temperature of about 170.degree. to 190.degree. F. After a period of time ranging from about 2 to 48 hours, the nibs are removed and dried then they are ready for grinding to produce alkali-processed chocolate liquor which is then pressed to obtain cocoa solids and cocoa butter. Compared with natural cocoa made from the same cleaned, roasted nibs without alkali processing, the alkalized product is much darker, milder in acid character, and has a pH in water solution of about 7.5; whereas, the natural cocoa will have a pH of about 5.4. The alkalized cocoa will have a reddish-brown color; the untreated cocoa will be light brown.
More recently, processes which focus on the dutching of cocoa powder have been described U.S. Pat. No. 4,435,436 to Terink et al. describes the production of cocoa powder, having a desirable dark color and a relatively low pH, by treating cocoa powder with potassium hydroxide at between 65.degree. and 90.degree. C., at atmospheric pressure, for from 4 to 24 hours. U.S. Pat. Nos. 3,868,469 and 3,997,680 to Chalin disclose a powder cocoa dutching process wherein cocoa powder is reacted with an aqueous alkaline solution in an extruder at a temperature of 150.degree. to 230.degree. F. and a mechanical pressure of 500 to 1,300 p.s.i. for 2.5 to 5 minutes.
Another recent cocoa alkalization process has been described in U.S. Pat. No. 4,784,866 to Wissgott wherein meal (i.e., crushed and degermed raw nibs) or liquor is alkalized without the evaporation of water under air pressure of from 1 to 3 atmospheres. According to this patent, alkalization is carried out at a temperature of 60.degree. to 100.degree. C. for 30 minutes to 4 hours to produce colors ranging from red to dark brown.